One degree Brix is 1 gram of sucrose in 100 grams ( w/w) of the solution If the solution contains dissolved solids other than pure sucrose, then the °Bx only
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[PDF] Brix
Mettler-Toledo allow to measure directly Brix degrees or HFCS Both measuring methods allow the automatic conversion of refractive index / density into Brix
[PDF] Refractive Index
One degree Brix is 1 gram of sucrose in 100 grams ( w/w) of the solution If the solution contains dissolved solids other than pure sucrose, then the °Bx only
[PDF] refractive index
Abbe refractometer The refractometer used must be fitted with a scale giving: - either percentage by mass of sucrose to 0 1 ; - or refractive indices to four decimal
[PDF] BRIX ANALYSIS
-Total soluble solids content of a solution is determined by the index of refraction This is measured using a refractometer, and is referred to as the degrees Brix -
[PDF] Sucrose conversion
In fruit juices the refractive index is therefore dependent upon sugar Table A: Acid Correction to the Brix value (Bx°) for high acid (Citrus) concentrates
Acid Corrections to the BRIX
THE LBS SOLIDS/GALLON FROM THE BRIX USING EQUATION 2-10 the calculator is in the USER mode refractive index to detect, in oils, 94 screening
[PDF] Computer Method for Calculating Percentage Apparent Purity of
Brix in this case is RDS Consider a sample of thin juice with a saccharimeter reading of 40 3 and a refractive index of 24 29 The RDS corresponding to this
[PDF] Honey refractometers measure moisture content Honey
Technically, refractometers measure the refractive index of a substance Explanation: 1 degree Brix (written °Bx ) means 1 g of sucrose per 100 g of aqueous
[PDF] brix to refractive index conversion equation
[PDF] brix to refractive index conversion table
[PDF] brix to refractive index converter
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Refractive Index
A refractometer measures the extent to which light is bent (i.e. refracted) when it moves from air into a sample and is typically used to determine the index of refraction(refractive index or n) of a liquid sample. The refractive index is a unitless number, between 1.3000 and 1.7000 for most compounds, and is normally determined to five digit precision. Since the index of refraction depends on both the temperature of the sample and the wavelength of light used these are both indicated when reporting the refractive index: The italicized n denotes refractive index, the superscript indicates the temperature in degrees Celsius, and the subscript denotes the wavelength of light (in this case the D indicates the sodium D line at 589 nm).In the organic chemistry laboratory, refractive index is commonly determined to help identify pure liquid
samples by comparing the experimental value to published values for pure compounds. However, there are many more applications for refractive index:Soluble solids in fruit products
Rancidity in edible oils
Moisture in honey and strawberry jam
Total solids, water and fat in milk
Oil in avocado and olives
Fat in chocolate
Moisture in meat
Petroleum in oil sands
Olefins, aromatics, paraffins
Ethylene glycol in coolants
Oil content of seeds
Sweet corn maturity
Salinity
Industrially, it is most often used to determine concentration of a dissolved solute in liquid samples. The
most common application is measuring the concentration of sugar dissolved in water, such as in fruit juices
and juice concentrates.Examples of smaller, hand-held refractometers:
Dissolved sugar changes the refractive index of water substantially. Since sugar is the primary ingredient in
Degrees Brix (symbol °Bx) is the sugar content of an aqueous solution. One degree Brix is 1 gram of
sucrose in 100 grams (% w/w) of the solution. If the solution contains dissolved solids other than pure
sucrose, then the °Bx only approximates the dissolved solid content. The °Bx is traditionally used in the
wine, sugar, fruit juice, and honey industries. Since temperature can affect refractive index, it is important to
control this parameter during a measurement. (One degree Celsius changes R.I. by about 0.0001 unit.)
When a sugar solution is measured by refractometer or densitometer, the R.I. or °Bx value only represents
the amount of dry solids dissolved in the sample if the dry solids are exclusively sucrose. This is seldom the
case. Grape juice, for example, contains little sucrose but does contain glucose, fructose, acids and other
substances. In such cases the °Bx value clearly cannot be equated with the sucrose content but it may
represent a good approximation to the total sugar content. For example, an 11.0 %w/w D-Glucose ("grape
sugar") solution measures 10.9 °Bx.When other solids are dissolved in the solution, they can affect the refractive index. For example, many fruit
juices contain citric acid that will increase the Brix value. Therefore, the citric acid is usually titrated and the
brix value is corrected from values in published tables. Note the differences in sugar concentrations between orange, grape, and lemon juices. When imported juices arrive (usually as juice concentrates), they are tested by U.the respective specification in the following table. The values in the lower part of the table are the actual
refractometer readings that represent the typical combined citric acid and sugars.When juice bottlers manufacture a fruit juice beverage, they purchase frozen juice concentrates on the
commodities market. The cost of these juices depends on their Brix value. The higher the Brix value, the
more concentrated the juice. The concentrates save on shipping and refrigeration costs. The concentrates
are diluted with water to the appropriate ratio as determined by the Brix numbers, and the resulting product is
pasteurized, filled, and sealed for sale. *Note: Brix correction = (0.1775 x % anhydrous citric acid) + 0.1343 Some industries utilize the Brix scale to measure solute concentrations that contain no sugar at all. Of course, in this case the brix scale is similar to POH UHIUMŃPLYH LQGH[" ÓXVP M QXPNHU POMP ŃMQ NH ŃMOLNUMPHG PR POH VSHŃLILŃ analytical method. A series of standards in prepared, measured, and then plotted. When an unknown containing the same solute is analyzed, the reading is compared to the chart to obtain the actual concentration. For example, the concentration of salt solutions or antifreeze can be easily measured by refractive index. However, alcohol water mixtures are not as easy. Note the refractive index values of the mixtures in the table below. Also note the density of ethanol and methanol in the same solutions.Relationship between Salt
Solution and Sugar
Concentration (Brix) and
refractive index at 20°CSalt(NaCl)
g/100gRefractive
Index Brix %
0 1.3330 0
1 1.3348 1.3
2 1.3366 2.5
3 1.3383 3.7
4 1.3400 4.8
5 1.3418 6.0
6 1.3435 7.2
7 1.3453 8.4
8 1.3470 9.5
9 1.3488 10.6
10 1.3505 11.7
11 1.3523 12.8
12 1.3541 14.9
13 1.3558 15.1
14 1.3576 16.1
15 1.3594 17.2
16 1.3612 18.4
17 1.3630 19.5
18 1.3648 20.6
19 1.3666 21.7
20 1.3684 22.7
21 1.3703 23.8
22 1.3721 24.9
23 1.3740 26.0
24 1.3759 27.1
25 1.3778 28.1
26 1.3797 29.2
US CUSTOMS TABLE OF CORRECTED BRIX VALUES FOR SELECTED JUICES*DEGREE OF
CONCENTRATION
ORANGE
JUICE GRAPE [VITIS VINIFERA] JUICELEMON JUICE
Unconcentrated
(No Citric acid correction)R.I Reading (°Bx)
11.8 21.5 8.9
Unconcentrated - 17.31 - 30.99 - 13.121.5 17.32 - 19.97 31.00 - 35.47 13.13 - 15.18
2.0 19.98 - 25.14 35.48 - 43.95 15.19 - 19.21
2.5 25.15 - 30.09 43.96 - 51.86 19.22 - 23.10
3.0 30.10 - 34.85 51.87 - 59.27 23.11 - 26.87
3.5 34.86 - 39.42 59.28 - 66.23 26.88 - 30.53
4.0 39.43 - 43.83 66.24 - 72.81 30.54 - 34.09
4.5 43.84 - 48.07 72.82 - 79.03 34.10 - 37.54
5.0 48.08 - 52.17 79.04 - 84.95 37.55 - 40.89
5.5 52.18 - 56.12 84.96 - 90.95 40.90 - 44.15
6.0 56.13 - 59.95 44.16 - 47.32
6.5 59.96 - 63.65 47.33 - 50.40
7.0 63.66 - 67.25 50.41 - 53.41
%(w/w)EthanolMethanolEthylene Glycol
0.500.99730.99730.9988
1.000.99630.99640.9995
2.000.99450.99471.0007
3.000.99270.99301.0019
4.000.99100.99131.0032
5.000.98930.98961.0044
6.000.98780.98801.0057
7.000.98620.98641.0070
8.000.98470.98481.0082
9.000.98330.98321.0095
10.000.98190.98161.0108
12.000.97920.97851.0134
14.000.97650.97551.0161
16.000.97390.97251.0188
18.000.97130.96951.0214
20.000.96870.96661.0241
24.000.96320.96061.0296
28.000.95710.95451.0350
32.000.95040.94821.0405
36.000.94310.94161.0460
40.000.93520.93471.0514
44.000.92690.92731.0567
48.000.91830.91961.0619
52.000.90950.91141.0670
56.000.90040.90301.0719
60.000.89110.89441.0765
62.000.88650.8901
64.000.88180.8856
66.000.87710.8810
68.000.87240.8763
70.000.86760.8715
72.000.86290.8667
74.000.85810.8618
76.000.85330.8568
78.000.84850.8518
80.000.84360.8468
82.000.83870.8416
84.000.83350.8365
86.000.82840.8312
88.000.82320.8259
90.000.81800.8204
92.000.81250.8148
94.000.80700.8089
96.000.80130.8034
98.000.79540.7976
100.000.78930.7917
0.7800
0.8300
0.8800
0.9300
0.9800
1.0300
1.0800
0.0020.0040.0060.0080.00100.00
% Organic (w/w)Density of Alcohol-Water
Mixtures
Ethylene
Glycol
Ethanol
Methanol
Honey contains a lot of sugar that can be determined by refractive index. Notice that the plot below shows the
refractive index as a function of water (not sugar) in the mixture. Hence, a negative slope is observed. The
concentration of the sugars is calculated as the remainder (100% - % water = % sugar). % (w/w)MethanolPropylene GlycolEthylene Glycol
GlycerolEthanol
0.501.33311.33351.33301.33361.3333
1.001.33321.33401.33391.33421.3336
2.001.33341.33501.33481.33531.3342
3.001.33361.33611.33581.33651.3348
4.001.33381.33711.33671.33761.3354
5.001.33411.33821.33771.33881.3360
6.001.33431.33931.33861.34001.3367
7.001.33461.34031.33961.34121.3374
8.001.33481.34141.34051.34241.3381
9.001.33511.34251.34151.34361.3388
10.001.33541.34361.34251.34481.3395
12.001.33591.34591.34441.34721.3410
14.001.33651.34821.34641.34961.3425
16.001.33701.35041.34841.35211.3440
18.001.33761.35281.35031.35471.3455
20.001.33811.35511.35231.35721.3469
24.001.33921.35971.35641.36241.3498
28.001.34021.36441.36051.36761.3524
32.001.34111.36901.36461.37301.3546
36.001.34191.37361.36871.37851.3566
40.001.34251.37801.37281.38411.3583
44.001.34291.38241.37691.38971.3598
48.001.34311.38671.38111.39541.3610
52.001.34311.39101.38511.40111.3621
56.001.34291.39521.38921.40691.3630
60.001.34261.39951.39311.41291.3638
64.001.34221.41891.3644
68.001.34151.42491.3650
72.001.34071.43101.3654
76.001.33971.43701.3657
80.001.33851.44311.3658
84.001.33721.44921.3656
88.001.33571.45531.3653
92.001.33391.46131.3646
96.001.33161.46741.3636
100.001.32901.47351.3614
1.3300
1.3400
1.3500
1.3600
1.3700
1.3800
1.3900
1.4000
1.4100
1.4200
0.0020.0040.0060.0080.00100.00
% Organic (w/w)Refractive Index of Selected Coolant
Solutions
Glycerol
Propylene
Glycol
Ethylene
Glycol
Ethanol
Methanol
Refractive Index Calibration of Glycerin/Water Mixtures (Brix Scale) %(w/w)°Bx°Bx Calibration0.0%0.0Slope73.59
70.0%53.2intercept0.482
80.0%60.2
90.0%66.2
100.0%73.0
Unknown Mixture of Glycerin in Water:
°Bx% Gycerin
Trial #154.873.8%
Trial #254.773.7%
Trial #354.873.8%
y = 65.4x + 7.56R² = 0.9992
50.055.0
60.0
65.0
70.0
75.0
70.0%80.0%90.0%100.0%
°Bx
Calibration of the refractometer is important. While published values are helpful, it is critical to insure the
instrument is measuring values correctly. Liquid solutions are prepared or purchased that are measured under
the same conditions as the samples. Here is an actual example of a test for glycerin (glycerol) in water. Four
standards were prepared by weighing out the appropriate masses of glycerin and water, preparing concentrations of 70%, 80%, 90%, and 100%(w/w). These were measured on the Abby refractometer on a cold day in the lab and the values differ slightly from the published values.